1. The Field of the Invention
This invention relates to vehicle proximity sensing devices and more particularly to that class adapted to detect the range of vehicles being passed by equipment soley contained on board the passing vehicle.
2. Description of the Prior Art
The prior art abounds with various devices utilized to detect speed or distance of adjacent vehicles. U.S. Pat. No. 3,716,822 issued on Feb. 13, 1973 to Y. Tsuruta teaches a supersonic wave utilizing the Doppler effect to detect the relative speed of a preceding vehicle and to apply the braking system automatically when the preceding vehicle is being operated at substantially slower speeds than the scrutinizing vehicle.
U.S. Pat. No. 3,841,427 issued on Oct. 15, 1974 to V. DiVita discloses a distance measuring device, utilizing radar waves to sense the distance from a preceding vehicle and to automically activate the scrutinizing vehicle's braking system.
The aforementioned inventions suffer the common deficiency of failing to provide ranging dnd detecting information when passing an adjacent vehicle.